Listings of available real estate are typically stored in a central computer system, generally referred to as a "multiple listing service". This computer-stored listing may be accessed through terminals for retrieval of specific information relating to a given property. However, search of the stored information is typically dependent on the operator's intricate knowledge of the local area, its political subdivisions, and informal housing tract designations. Furthermore, such listings are usually maintained for each county, and multiple accesses of diverse systems are often required for a complete location of all available properties. Finally, no provision for searches by multiple criteria, including geographic location is made in prior systems.